A. Safonov

In this paper, we review recent theoretical progress and the latest experimental results in jet substructure from the Tevatron and the LHC. We review the status of and outlook for calculation and simulation tools for studying jet substructure. Following up on the report of the Boost 2010 workshop, we present a new set of benchmark comparisons of substructure techniques, focusing on the set of variables and grooming methods that are collectively known as 'top taggers'. To facilitate further exploration, we have attempted to collect, harmonize and publish software implementations of these techniques.

Accurate reconstruction of the mass of a resonance decaying to a pair of τ leptons is challenging because of the presence of multiple neutrinos from τ decays. The existing methods rely on either a partially reconstructed mass, which has a broad spectrum that reduces sensitivity, or the collinear approximation, which is applicable only to the relatively small fraction of events. We describe a new technique, which provides an accurate mass reconstruction of the original resonance and does not suffer from the limitations of the collinear approximation. The major improvement comes from replacing assumptions of the collinear approximation by a requirement that mutual orientations of the neutrinos and other decay products are consistent with the mass and decay kinematics of a τ lepton. This is achieved by maximizing a probability defined in the kinematically allowed phase space region. In this paper we describe the technique and illustrate its performance using Z/γ⁎→ττ and H→ττ events simulated with the realistic detector resolution. The method is also tested on a clean sample of data Z/γ⁎→ττ events collected by the CDF experiment at the Tevatron. We expect that this new technique will allow for a major improvement in searches for the Higgs boson at both the LHC and the Tevatron.

This report of the BOOST2012 workshop presents the results of four working groups that studied key aspects of jet substructure. We discuss the potential of first-principle QCD calculations to yield a precise description of the substructure of jets and study the accuracy of state-of-the-art Monte Carlo tools. Limitations of the experiments' ability to resolve substructure are evaluated, with a focus on the impact of additional (pile-up) proton proton collisions on jet substructure performance in future LHC operating scenarios. A final section summarizes the lessons learnt from jet substructure analyses in searches for new physics in the production of boosted top quarks.

We describe the initial performance of the detector used for the luminosity measurement in the CDF experiment in Run II at the Tevatron. The detector consists of low-mass gaseous Cherenkov counters with high light yield (∼100 photoelectrons) and monitors the process of inelastic pp̄ scattering. It allows for several methods of precise luminosity measurements at peak instantaneous luminosities of 2×1032cm−2s−1, corresponding to an average of six pp̄ interactions per bunch crossing.

We analyze the prospects for resonant di-Higgs production searches at the LHC in the $b\bar{b} W^+ W^-$ ($W^{+} \to \ell^{+} \nu_{\ell}$, $W^{-} \to \ell^{-} \bar{\nu}_{\ell}$) channel, as a probe of the nature of the electroweak phase transition in Higgs portal extensions of the Standard Model. In order to maximize the sensitivity in this final state, we develop a new algorithm for the reconstruction of the $b \bar{b} W^+ W^-$ invariant mass in the presence of neutrinos from the $W$ decays, building from a technique developed for the reconstruction of resonances decaying to $\tau^{+}\tau^{-}$ pairs. We show that resonant di-Higgs production in the $b\bar{b} W^+ W^-$ channel could be a competitive probe of the electroweak phase transition already with the datasets to be collected by the CMS and ATLAS experiments in Run-2 of the LHC. The increase in sensitivity with larger amounts of data accumulated during the High Luminosity LHC phase can be sufficient to enable a potential discovery of the resonant di-Higgs production in this channel.

This report describes both the technical design and the expected performance of the Phase-II upgrade, using Gas Electron Multiplier (GEM) detectors, of the first endcap station of the CMS muon system. The upgrade is targeted for the second long shutdown of the CERN LHC and is designed to improve the muon trigger and tracking performance at high luminosity. The GEM detectors will add redundancy to the muon system in the 1.6 < |η| < 2.2 pseudorapidity region, where the amount of detection layers is lowest while the background rates are highest and the bending of the muon trajectories due to the CMS magnetic field is small. GEM detectors have been identified as a suitable technology to operate in the high radiation environment present in that region. The first muon endcap station will be instrumented with a double layer of triple-GEM chambers in the 1.6 < |η| < 2.2 region. The detector front-end electronics uses the custom designed VFAT3 chip to provide both fast input for the level-1 muon trigger and full granularity information for offline muon reconstruction. This document describes the design of detectors, electronics, and services. The expected performance of the upgraded muon system is discussed in the context of several benchmark physics channels. The document also presents the plan - including the project schedule, cost, and organization - for the detector construction, testing, and integration into the CMS detector.

We have built a novel device for precision measurements of luminosity in the CDF experiment at the high pp̄ collision rates expected during Run II. The detector consists of long, conical, gaseous Cherenkov counters that point to the collision region and monitor the average number of inelastic pp̄ interactions by measuring the number of particles, and their arrival time, in each bunch crossing. For these primary particles, using isobutane at atmospheric pressure as a radiator, a large amount of Cherenkov light (∼100 photoelectrons) will be collected, with good amplitude and time resolutions, onto small and efficient PMTs. Suitable amplitude thresholds will be applied to discriminate from non-primary particles and other backgrounds which yield little light in the counters. This detector is expected to reliably perform bunch-by-bunch luminosity measurements at peak instantaneous luminosities of 2×1032 cm−2 s−1 with six interactions per bunch crossing, on average, and respond to a 132 ns bunch spacing.

We explore the potential of the Large Hadron Collider to observe the ${h}_{1}\ensuremath{\rightarrow}{a}_{1}{a}_{1}\ensuremath{\rightarrow}4\ensuremath{\mu}$ signal from the lightest scalar Higgs boson (${h}_{1}$) decaying into the two lightest pseudoscalar Higgs bosons (${a}_{1}$), followed by their decays into four muons in the next-to-minimal supersymmetric standard model (NMSSM). The signature under study applies to the region of the NMSSM parameter space in which ${m}_{{a}_{1}}&lt;2{m}_{\ensuremath{\tau}}$, which has not been studied previously. In such a scenario, the suggested strategy of searching for a four-muon signal with the appropriate background suppression would provide a powerful method to discover the lightest $CP$-even and $CP$-odd NMSSM Higgs bosons ${h}_{1}$ and ${a}_{1}$.

The CMS GEM collaboration is performing a feasibility study to install triple-GEM detectors in the forward region of the muon system (1.6 < |η| < 2.4) of the CMS detector at the LHC. Such micro-pattern gas detectors are able to cope with the extreme particle rates that are expected in that region during the High Luminosity phase of the LHC. With their spatial resolution of order 100 micron GEMs would not only provide additional benefits in the CMS muon High Level Trigger, but also in the muon identification and track reconstruction, effectively combining tracking and triggering capabilities in one single device. The present status of the full project will be reviewed, highlighting all importants steps and achievements since the start of the R&amp;D in 2009. Several small and full-size prototypes were constructed with different geometries and techniques. The baseline design of the triple-GEM detector for CMS will be described, along with the results from extensive test measurements of all prototypes both in the lab and in test beams at the CERN SPS. The proposed on- and off-detector electronics for the final system will be presented.

We describe here a novel approach to luminosity measurements for pp̄ collider experiments. We propose to use low-pressure gaseous Cherenkov counters at small angles relative to the beam direction to determine the rate of inelastic pp̄ interactions. With a propotype counter, we measured at a beam test a light yield of over 100 photoelectrons and a timing resolution of better than 50 ps. The CDF collaboration will use a detector based on this technique for luminosity measurements at the upgraded Tevatron collider.

We have implemented triggers for hadronically decaying tau leptons within a framework of the CDF Run 2 trigger system. We describe the triggers, along with their physics motivations, and report on their initial performance.

The electronics used in the data readout and triggering system for the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) particle accelerator at CERN are exposed to high radiation levels. This radiation can cause permanent damage to the electronic circuitry, as well as temporary effects such as data corruption induced by Single Event Upsets. Once the High Luminosity LHC (HL-LHC) accelerator upgrades are completed it will have five times higher instantaneous luminosity than LHC, allowing for detection of rare physics processes, new particles and interactions. Tests have been performed to determine the effects of radiation on the electronic components to be used for the Endcap Muon electronics project currently being designed for installation in the CMS experiment in 2013. During these tests the digital components on the test boards were operating with active data readout while being irradiated with 55 MeV protons. In reactor tests, components were exposed to 30 years equivalent levels of neutron radiation expected at the HL-LHC. The highest total ionizing dose (TID) for the muon system is expected at the inner-most portion of the CMS detector, with 8900 rad over ten years. Our results show that Commercial Off-The-Shelf (COTS) components selected for the new electronics will operate reliably in the CMS radiation environment.

During the next shutdown of the LHC at CERN, the CMS experiment plans to start installing GEM detectors in the endcap (high pseudorapidity) region. These muon detectors have excellent spatial and temporal resolution as well as a high chemical stability and radiation hardness. A report is given on preliminary results of materials studies that aimed to fully characterize the GEM detector components before and after the exposure to a high-radiation environment.

The LHC data-taking will resume in 2015 with energy of 13–14 TeV and luminosity of 2÷5 × 1034 cm−2 s−1. At those energies, a considerable fraction of the particles produced propagate in the high pseudo-rapidity regions. The proposal for the upgrade of the CMS muon forward system involves Gas Electron Multiplier (GEM) chambers to be installed during the second LHC Long Shutdown (LS2) covering the pseudorapidity range 1.5 < |η| < 2.2. This detector is able to handle the extreme particle rates expected in this region when the LHC will be running at higher luminosity. The GEM is an excellent choice, as its high spatial resolution (order of 100 μm) allows to combine tracking and triggering capabilities, which will improve the CMS muon High Level Trigger, the muon identification and the track reconstruction. Intense R&D has been going on since 2009 and it has lead to the development of several GEM prototypes and associated detector electronics. These GEM prototypes have been subjected to extensive tests in the laboratory and in test beams at the CERN Super Proton Synchrotron (SPS). This contribution will review the status of the CMS upgrade project with GEMs, discussing also the trigger performance.

After the Phase-2 high-luminosity upgrade to the Large Hadron Collider (LHC), the collision rate and therefore the background rate will significantly increase, particularly in the high $\eta$ region. To improve both the tracking and triggering of muons, the Compact Muon Solenoid (CMS) Collaboration plans to install triple-layer Gas Electron Multiplier (GEM) detectors in the CMS muon endcaps. Demonstrator GEM detectors were installed in CMS during 2017 to gain operational experience and perform a preliminary investigation of detector performance. We present the results of triple-GEM detector performance studies performed in situ during normal CMS and LHC operations in 2018. The distribution of cluster size and the efficiency to reconstruct high $p_T$ muons in proton--proton collisions are presented as well as the measurement of the environmental background rate to produce hits in the GEM detector.

The international CMS GEM collaboration is studying the feasibility of upgrading the CMS forward muon system by adding layers of triple GEM based detectors. After successful tests of small size tripe-GEM chambers in the period of 2010-2011, the collaboration has designed, built and tested full-size GEM chambers for the upgrade purpose. We report on results from test beam and simulation that were conducted to study the performance of the GEM chambers.

Presented are the most recent jet fragmentation results from CDF: inclusive distributions of charged particle momenta and their kT in jets; average track multiplicities, as well as angular distributions of multiplicity flow, for a wide range of jet energies with ET from 40 to 300 GeV. The results are compared with Monte-Carlo and, when possible, analytical calculations performed in resummed perturbative QCD approximations (MLLA).

In this contribution we will report on the progress of the design of the readout and data acquisition system being developed for triple-GEM detectors which will be installed in the forward region (1.5 < |η| < 2.2) of the CMS muon spectrometer during the 2nd long shutdown of the LHC, expected in the period 2017–2018. The system will be designed to take full advantage of current generic developments introduced for the LHC upgrades. The current design is based on the use of CERN GLIB boards hosted in micro-TCA crates for the off-detector electronics and the Versatile Link with the GBT chipset to link the front-end electronics to the GLIB boards. In this contribution we will describe the physics goals, the hardware architectures and report on the expected performance of the CMS GEM readout system, including preliminary timing resolution simulations.

Higgs portal interactions provide a simple mechanism for addressing two open problems in cosmology: dark matter and the baryon asymmetry. In the latter instance, Higgs portal interactions may contain the ingredients for a strong first-order electroweak phase transition as well as new CP-violating interactions as needed for electroweak baryogenesis. These interactions may also allow for a viable dark matter candidate. We survey the opportunities for probing the Higgs portal as it relates to these questions in cosmology at the LHC and possible future colliders.

In the Compact Muon Solenoid (CMS) experiment, muon detection in the forward direction is accomplished by cathode strip chambers (CSC). These detectors identify muons, provide a fast muon trigger, and give a precise measurement of the muon trajectory. There are 468 six-plane CSCs in the system. The efficiency of finding muon trigger primitives (muon track segments) was studied using 36 CMS CSCs and cosmic ray muons during the Magnet Test and Cosmic Challenge (MTCC) exercise conducted by the CMS experiment in 2006. In contrast to earlier studies that used muon beams to illuminate a very small chamber area (<0.01m2), results presented in this paper were obtained by many installed CSCs operating in situ over an area of ≈23m2 as a part of the CMS experiment. The efficiency of finding two-dimensional trigger primitives within six-layer chambers was found to be 99.93±0.03%. These segments, found by the CSC electronics within 800 ns after the passing of a muon through the chambers, are the input information for the Level-1 muon trigger and, also, are a necessary condition for chambers to be read out by the Data Acquisition System.

Overview The High Energy Physics Group at Texas A&M University is submitting this final report for our grant number DE-FG02-95ER40917. This grant has supported our wide range of research activities for over a decade. The reports contained here summarize the latest work done by our research team. Task A (Collider Physics Program): CMS & CDF Profs. T. Kamon, A. Safonov, and D. Toback co-lead the Texas A&M (TAMU) collider program focusing on CDF and CMS experiments. Task D: Particle Physics Theory Our particle physics theory task is the combined effort of Profs. B. Dutta, D. Nanopoulos, and C. Pope. Task E (Underground Physics): LUX & NEXT Profs. R. Webb and J. White(deceased) lead the Xenon-based underground research program consisting of two main thrusts: the first, participation in the LUX two-phase xenon dark matter search experiment and the second, detector R&D primarily aimed at developing future detectors for underground physics (e.g. NEXT and LZ).

The paper studies the effect of rearing in stocking ponds using the warm discharge water of the Smolensk NPP on the growth and trout meat quality. Some morphological indicators of trout cultivation are presented. The histological studies of the musculature of golden and typically colored trout are presented. It was revealed that the golden trout musculature grows with a predominance of hyperplasia of muscle fibers compared to the typically colored trout. It was shown that trout rearing using NPP cooling ponds does not lead to excessive accumulation internal fat and gives good results.

In this contribution, we describe the hadronic tau reconstruction and identification procedures adopted by the CDF experiment at Fermilab and present an overview of physics studies using tau leptons that are underway at CDF. Recent results using data obtained from Run II of the Tevatron are presented and include precision electroweak measurements as well as studies aimed at beyond Standard Model searches for new particles and interactions.

We present the scope of research of a new collaboration FLAP (Fundamental & applied Linear Accelerator Physics collaboration) devoted to the study of the basics of electromagnetic interactions and new applications of controllable generation of electromagnetic radiation by relativistic electrons using functional materials.

Long-lived particles (LLPs) are highly motivated signals of physics Beyond the Standard Model (BSM) with great discovery potential and unique experimental challenges. The LLP search programme made great advances during Run 2 of the Large Hadron Collider (LHC), but many important regions of signal space remain unexplored. Dedicated triggers are crucial to improve the potential of LLP searches, and their development and expansion is necessary for the full exploitation of the new data. The public discussion of triggers has therefore been a relevant theme in the recent LLP literature, in the meetings of the LLP@LHC Community workshop and in the respective experiments. This paper documents the ideas collected during talks and discussions at these Workshops, benefiting as well from the ideas under development by the trigger community within the experimental collaborations. We summarise the theoretical motivations of various LLP scenarios leading to highly elusive signals, reviewing concrete ideas for triggers that could greatly extend the reach of the LHC experiments. We thus expect this document to encourage further thinking for both the phenomenological and experimental communities, as a stepping stone to further develop the LLP@LHC physics programme.

Higgs portal interactions provide a simple mechanism for addressing two open problems in cosmology: dark matter and the baryon asymmetry. In the latter instance, Higgs portal interactions may contain the ingredients for a strong first order electroweak phase transition as well as new CP-violating interactions as needed for electroweak baryogenesis. These interactions may also allow for a viable dark matter candidate. We survey the opportunities for probing the Higgs portal as it relates to these questions in cosmology at the LHC and possible future colliders.

Algorithms based on the particle flow approach are becoming increasingly utilized in collider experiments due to their superior jet energy and missing energy resolution compared to the traditional calorimeter-based measurements. Such methods have been shown to work well in environments with low occupancy of particles per unit of calorimeter granularity. However, at higher instantaneous luminosity or in detectors with coarse calorimeter segmentation, the overlaps of calorimeter energy deposits from charged and neutral particles significantly complicate particle energy reconstruction, reducing the overall energy resolution of the method. We present a technique designed to resolve overlapping energy depositions of spatially close particles using a statistically consistent probabilistic procedure. The technique is nearly free of ad-hoc corrections, improves energy resolution, and provides new important handles that can improve the sensitivity of physics analyses: the uncertainty of the jet energy on an event-by-event basis and the estimate of the probability of a given particle hypothesis for a given detector response. When applied to the reconstruction of hadronic jets produced in the decays of tau leptons using the CDF-II detector at Fermilab, the method has demonstrated reliable and robust performance.

The study of processes containing T leptons in the final state will play an important role at Tevatron Run II. Such final states will be relevant both for electroweak studies and measurements as well as in searches for physics beyond the Standard Model. The present paper discusses the physics opportunities and challenges related to the implementation of a new set of triggers able to select events containing tau candidates in the final state. We illustrate, in particular, the physics capabilities for a variety of new physics scenarios such as supersymmetry (SUSY), SUSY with Rp-parity violation, with Bilinear parity violation or models with the violation of lepton flavor. Finally, we present the first Run II results obtained using some of the described tau triggers.

The production, installation, and testing of 468 cathode strip chambers for the endcap muon system of the CMS experiment played a critical role in the preparation of the endcap muon system for the final commissioning. Common testing procedures and sets of standard equipment were used at 5 international assembly centers. The chambers were then thoroughly retested after shipment to CERN. Final testing was performed after chamber installation on the steel disks in the CMS detector assembly building. The structure of the detector quality control procedure is presented along with the results of chamber performance validation tests.

An estimate of environmental background hit rate on triple-GEM chambers is performed using Monte Carlo (MC) simulation and compared to data taken by test chambers installed in the CMS experiment (GE1/1) during Run-2 at the Large Hadron Collider (LHC). The hit rate is measured using data collected with proton-proton collisions at 13 TeV and a luminosity of 1.5$\times10^{34}$ cm$^{-2}$ s$^{-1}$. The simulation framework uses a combination of the FLUKA and Geant4 packages to obtain the hit rate. FLUKA provides the radiation environment around the GE1/1 chambers, which is comprised of the particle flux with momentum direction and energy spectra ranging from $10^{-11}$ to $10^{4}$ MeV for neutrons, $10^{-3}$ to $10^{4}$ MeV for $\gamma$'s, $10^{-2}$ to $10^{4}$ MeV for $e^{\pm}$, and $10^{-1}$ to $10^{4}$ MeV for charged hadrons. Geant4 provides an estimate of detector response (sensitivity) based on an accurate description of detector geometry, material composition and interaction of particles with the various detector layers. The MC simulated hit rate is estimated as a function of the perpendicular distance from the beam line and agrees with data within the assigned uncertainties of 10-14.5%. This simulation framework can be used to obtain a reliable estimate of background rates expected at the High Luminosity LHC.

New light bosons that couple weakly to the standard model (SM) particles are predicted in various extensions of the standard model (BSM). Examples include supersymmetric (SUSY) theories with extended Higgs sectors or with a hidden valleys (dark SUSY). In these models the light bosons can be produced directly in the decay of a Higgs boson, or as part of the decay chain of SUSY particles. Depending on the branching fraction, the exotic decays of the SM-Higgs can be undetected in standard analysis techniques or due to its modified production cross section of the Higgs bosons at the LHC. Therefore, direct searches for non-SM decays of the Higgs boson are the fastest way to understand the nature of the Higgs boson. Either it will confirm its SM character, or it will rule out a whole array of BSM scenarios. We present status of the search at CMS for non-SM Higgs boson decays in events with displaced muon-jets.

New light bosons that couple weakly to the standard model (SM) particles are predicted in various extensions of the standard model (BSM). Examples include supersymmetric (SUSY) theories with extended Higgs sectors or with a hidden valleys (dark SUSY). In these models the light bosons can be produced directly in the decay of a Higgs boson, or as part of the decay chain of SUSY particles. Depending on the branching fraction, the exotic decays of the SM-Higgs can be undetected in standard analysis techniques or due to its modified production cross section of the Higgs bosons at the LHC. Therefore, direct searches for non-SM decays of the Higgs boson are the fastest way to understand the nature of the Higgs boson. Either it will confirm its SM character, or it will rule out a whole array of BSM scenarios. We present status of the search at CMS for non-SM Higgs boson decays in events with displaced muon-jets.

Based on the CMS Upgrade R&amp;D Proposal RD10.02, we describe the motivation and main features of the CMS GEM Project for LS2 and propose the addition of a full GE1/12 detector station comprising Gas Electron Multiplier (GEM) chambers to the forward muon system of CMS. The limitations of the currently existing forward muon detector when operating at increasingly high luminosity expected after LS1 are laid out followed by a brief description of the anticipated performance improvements achievable with a GE1/1 station. The second part describes the detector system followed by an overview of electronics and associated services including a discussion of the schedule and cost of the project. Plans for a precursor demonstrator installation in LS1 are presented. This proposal is intended as a concise follow-up of the detailed document CMS-IN-2012-023. If approved, this is to be followed by a detailed Technical Design Report.

Before the LHC experiments have accumulated significant amounts of data, the Tevatron experiments remain the frontier of searches for Higgs, both in the context of the Standard Model as well as scenarios of new physics.With both the CDF and DØ experiments in a smooth operating regime and well understood detectors and data, the focus of both experiments is now on improving the sensitivity of searches with the existing data by utilizing advanced analysis methods.This contribution reports on the status and perspectives of the searches for Higgs boson at Fermilab Tevatron.

The CMS collaboration used the past year to greatly improve the level of detector readiness for the first collisions data. The acquired operational experience over this year, large gains in understanding the detector and improved preparedness for early physics will be instrumental in minimizing the time from the first collisions to first LHC physics. The following describes the status of the CMS experiment and outlines early physics plans with the first LHC data.

This contribution reports on some of the most recent searches for new heavy neutral bosons and leptoquarks performed at the Tevatron experiments.

We present recent CDF results in the area of electroweak physics based on 350-1000 pb{sup -1} of Run II data.

In order to find the possibilities of increasing further the current of the accelerated protons in the synchrocyclotron, a more accurate quantitative calculation of the efficiency of capture into the stable radial-phase oscillations was made. The calculation was based on the analysis of the radial- phase ion trajectories in the central region of the synchrocyclotron. The trajectories, in their turn, were obtained just from the solutions of the equations for the ion motion in the electromagnetic field. The capture regions were determined as a function of the synchrocyclotron parameters: the dee aperture, the amplitude of the accelerating voltage, the gradient of the magnetic field, and the rate of change of the accelerating voltage frequency. A mechanism for formation of the accelerated ion beam in the initial region of acceleration was obtained. (auth)

Results are reported of work carried out between the years 1961-62 on the shaping of the r.f. characteristics of the 6-metre synchrocyclotron at the Joint Institute for Nuclear Research. These results have permitted optimum conditions for both capture and acceleration of the protons in the beam to be satisfied simultaneously up to the final radius with virtually no phase losses, as a result of which the current of accelerated protons at the final radius has been increased from 0.3 to 1.1-1.2 μA.

BS>The capture of particles and their phase shift to a finite radius during the acceleration process must be taken irto consideration when analyzing the characteristics of the phasotron; the frequency and the amplitude of the accelerating voltage needed to accelerate the particles to their ultimate radius must be at their maximum. These characteristics of the phasotron of the Joint Institute for Nuclear Studies were determined during 1961/62. The proton energies were measured as functions of the orbital radius and of the potential field of the duant of the ion source and of the accelerating chamber of the phasotron. On the basis of the results obtained, it was found possible to provide simultaneously optimal conditions for both the capture and the acceleration of the proton beam to its ultimate radius without phase loss. The data indicated that the value of the accelerated proton flux at the ultimate radius was increased from 0.3 to 1.1 to 1.2 mu amp. (TTT)

The latest results on jet physics at CDF are presented and discussed. Particular attention is paid to studies of the inclusive jet cross section using 177 pb{sup -1} of Run II data. Also discussed is a study of gluon and quark jet fragmentation.

Abstract A method for the determination of the radial and axial betatron oscillation amplitudes of the synchrocyclotron beam particles is described. This method has made it possible to find the distribution of particles as a function of the amplitude (an oscillation spectrum). For the Dubna synchrocyclotron the values of radial and axial betatron oscillations at the full radius are 15 cm and 2 cm, respectively.

For Run II, both CDF and D0 underwent significant improvement of the detectors to enhance their sensitivity to new physics. The detectors are commissioned and are taking data. The Tevatron is operating at a record center of mass energy of 1.96 TeV. Despite earlier difficulties, the luminosity situation is improving and both detectors have accumulated amounts of data comparable or higher than those available in Run I. This is a report on the status and prospects of SUSY searches at CDF and D0 in Run II. Recent SUSY analyses from run I are also reported.

In this paper, the most recent results on jet fragmentation obtained at the Collider Detector at Fermilab Tevatron are presented. The multiplicity and momentum distribution of charged particles inside jets in dijet events are compared to the predictions of the Modified Leading Log Approximation complemented with the hypothesis of Local Parton-Hadron Duality. Values for the two parameters of the model are extracted, the cut-off scale Q{sub eff} = 230 {+-} 40 MeV and the rate of parton-to-hadron conversions K{sub LPHD}{sup charged} = 0.56 {+-} 0.10. A fit of the data for the ratio of multiplicities in gluon and quark jets r, where r is treated as a free parameter, results in r = 1.9 {+-} 0.5. Also, we compare the charged particle multiplicities in dijet and {gamma}-jet events. The comparison allows for an extraction of a model-independent ratio of multiplicities in gluon and quark jets. We report r = N{sub g}/N{sub q} = 1.61 {+-} 0.11(stat) {+-} 0.28(syst) for E{sub jet} = 40 GeV.

Long-lived particles (LLPs) are highly motivated signals of physics Beyond the Standard Model (BSM) with great discovery potential and unique experimental challenges. The LLP search programme made great advances during Run 2 of the Large Hadron Collider (LHC), but many important regions of signal space remain unexplored. Dedicated triggers are crucial to improve the potential of LLP searches, and their development and expansion is necessary for the full exploitation of the new data. The public discussion of triggers has therefore been a relevant theme in the recent LLP literature, in the meetings of the LLP@LHC Community workshop and in the respective experiments. This paper documents the ideas collected during talks and discussions at these Workshops, benefiting as well from the ideas under development by the trigger community within the experimental collaborations. We summarise the theoretical motivations of various LLP scenarios leading to highly elusive signals, reviewing concrete ideas for triggers that could greatly extend the reach of the LHC experiments. We thus expect this document to encourage further thinking for both the phenomenological and experimental communities, as a stepping stone to further develop the LLP@LHC physics programme.

Recent CDF results in inclusive momentum distributions and multiplicities of particles in restricted cones around jets are compared to predictions using the Modified Leading Log Approximation. The authors found that MLLA gives a very reasonable description of jet fragmentation for a wide range of energies. Model parameters are extracted separately from the multiplicity and from the shape of the momentum distributions and are found to agree. The ratio of charged particle multiplicities in the gluon and quark jets measured in the context of MLLA is compared to the model-independent result and also found to agree.

This dissertation is dedicated to the experimental analysis of jet fragmentation, the process of formation of jets of particles produced in high-energy collisions, and to the comparison of the results to the predictions of resummed perturbative calculations within Quantum Chromodynamics.

Recent CDF results on inclusive momentum distributions and multiplicities of particles in restricted cones around jets are compared to predictions using the Modified Leading Log Approximation. We found that MLLA gives a very reasonable description of jet fragmentation for a wide range of energies. Model parameters are extracted separately from the multiplicity and from the shape of the momentum distributions and are found to agree. The ratio of charged particle multiplicities in gluon and quark jets measured in the context of MLLA is compared to the model-independent result and also found to agree.

Light-emitting dendrimers are a new distinct class of material for OLEDs. Dendrimers consist of a light-emitting core, dendrons and surface groups. Dendrimers are designed for solution coating and have a number of advantages over conjugated polymers. We report our recent results for solution processed green dendrimer OLEDs. The OLEDs were fabricated by spin-coating a blend of first generation dendrimer/host material followed by the evaporation of a hole blocking layer and a LiF/Al cathode. Power efficiencies of 50 lm/W at practical brightness levels were achieved for these structures.

In this paper, the most recent results on jet fragmentation obtained at the Collider Detector at Fermilab Tevatron are presented. The multiplicity and momentum distribution of charged particles inside jets in dijet events are compared to the predictions of the Modified Leading Log Approximation complemented with the hypothesis of Local Parton-Hadron Duality. Values for the two parameters of the model are extracted, the cut-off scale Q{sub eff} = 230 {+-} 40 MeV and the rate of parton-to-hadron conversions K{sub LPHD}{sup charged} = 0.56 {+-} 0.10. A fit of the data for the ratio of multiplicities in gluon and quark jets r, where r is treated as a free parameter, results in r = 1.9 {+-} 0.5. Also, we compare the charged particle multiplicities in dijet and {gamma}-jet events. The comparison allows for an extraction of a model-independent ratio of multiplicities in gluon and quark jets. We report r = N{sub g}/N{sub q} = 1.61 {+-} 0.11(stat) {+-} 0.28(syst) for E{sub jet} = 40 GeV.

Presented are the most recent jet fragmentation results from CDF: inclusive distributions of charged particle momenta and their k{sub T} in jets; average track multiplicities, as well as angular distributions of multiplicity flow, for a wide range of jet energies with E{sub T} from 40 to 300 GeV. The results are compared with Monte-Carlo and, when possible, analytical calculations performed in resumed perturbative QCD approximations (MLLA).